He'll probably end up liking pizza and the drummer's girlfriend. In that order.
 
Also, tell him to show you the bass stance and the bass face.
 
If he can do those, ask him about Am bass note. If he shows it to you get him an Alembic (I hear they're rather good) and a Mark Bass amp.
 
 

In the spirit of an earlier discussion, I'm guessing you mean this:
                                    
 
and not this:
                                                                     
 
 
 
Well, the nice thing is that you could be in for some nice father/son bonding if you play together in the same musical situation, helping to create beautiful, well-crafted renditions of tunes in which you both have an interest.
 
Or alternatively, you could come to vicious blows as you scream at each other about rhythmic feel.
 
Either way, you have a ton to which to look forward!
 
But this has a certain sense to it, don't you think? Your son already plays trombone well (and trombone is a noble instrument whose practitioners are next in bountifulness only to MBA recipients and drummers on most unemployment lines. Trombonists are also the subject of numerous humorous anecdotes, often related to their employment status. Google it; you'll catch what I mean). You bought him a guitar (guitarists are probably fourth in terms of population on the aforementioned unemployment lines, although admittedly often faring better in dating scenarios). So, he, being no slouch in the grey matter department, opts for an instrument that pretty much guarantees one a gig as long as one can fog a mirror.
 
Seriously, if he can be reliable and decent at the instrument, he'll probably work. If he doubles on the acoustic, so much better the chances. It could be worse.
 
May I make one suggestion: there are many inexpensive basses out there with necks that will warp badly inside of a year, making it pretty much certain that your son (if he plays one of these) will win an award in the Gnarly Buzz and Indefinite Pitch division of your local "Musicians Most Likely to Make Us Want to Hurl" Contest. Don't buy him one of these instruments! Spend just a little extra and get him a decent instrument, maybe even an older, well-cared-for instrument. 
 
                                        
 
                                       This visual aid is designed to assist in the proper interpretation of the properly realistic dating expectations
                                                                                                   of the average rock band aggregation.
                                                                          Just in case some poor bassist somewhere begins to get his hopes up.

outland144k
... 
 
 ...

 
I would say this picture is slightly off kilter ... that singer not being very good, will end up having nothing and that bass player not being a stooge for the drums and the guitar player, will probably get more girls than all the others together.
 
You should show that to Bootsie ... he'll tell you the real story!

quantumeffect
- My son has been playing trombone in the middle school band now for a couple of years and has gotten very good at it.
 
- I’ve always told my kids that they are free to use any of my drum kits and I would support them if they had any interest in the drums (neither go near the drums).
 
- I bought my son a short neck ESP guitar and gave him my Vox practice amp a while ago and he recently started showing some interest in it.
 
Two days ago my son said the words to me that I think every parent dreads:
 
“I know you are going to be mad at me but I want to learn how to play the bass”
 
I simply don’t know what to do … any advice?

Easy fix.  Force him to pay rent.  He'll either move to freeload on someone else's couch or snap out of it and take up guitar. 

I just don't want him winding up locked in a hot van somewhere ...
 
http://thehardtimes.net/2016/06/24/irresponsible-musicians-leave-bassist-hot-van/
 
 

outland144k
 
 Well, the nice thing is that you could be in for some nice father/son bonding if you play together in the same musical situation, helping to create beautiful, well-crafted renditions of tunes in which you both have an interest.
 

He we can be seen playing together.  OK, so we are not going to win any "Down Beat Magazine" awards but I definitely have a cool trumpet face.
 
https://www.youtube.com/watch?v=a6rA_07qCxU&feature=youtu.be
 
 
 
 
(here is my excuse - I gave the horn up as a kid and Am now an adult student at about the same playing level as my kids)

Nice to see your children involved in music. Once they experiment with various instruments, I'm sure they'll find one (or more) that'll truly interest them to spend the time on it (even bass).
 
I think I saw some fish jumping around during that performance.... 

Dave,
 
What VSTi did you use for the "wind" effect in that vid?