Son having trouble peeing ?

Last month my 11 y/o son was taking a very long time in the bathroom. Jokingly when I walked by I yelled out “is everything alright in there?” To my shock he said no. When he came out he admitted he has been having trouble peeing recently and when he does it doesn’t all come out.

I asked him if he had any other symptoms of a UTI and he said no. He wanted me to watch him so I did. Like he said it was only a trickle coming out and it took forever. He had to pull on his penis to get it out. One thing I noticed that concerned me is his penis is extremely long. I’m wondering if it’s causing the pee to get stuck. It sounds ridiculous but based on how he had to straighten out his penis before he was able to pee it looks as if that’s what’s happening. I haven’t told him because I don’t want to freak him out but if that’s the case I have no idea what to do.