4 week old Guinea pig penis keeps protruding out

[YodelingYotes]

Hello! One of my Guinea pigs is 4 weeks old, and with wiping and warm water his penis will go back in, but then start poking back out once again shortly after. Not only this but poop keeps sticking to his penis when it is out. I clean it off every time, but I don’t understand why this keeps happening and what I can do to help him out. I tried looking at a lot of threads in here and found somewhat related cases, but nothing I could use
It doesn’t stick out by a lot, but still.

 

[piggieminder]

Bump

 

[Wheekallweek]

I'd take him along to a vet for an examination
It could perhaps be a birth defect?
Good luck!