Boyfriends penis stinks

So my and I have been together 2 years. I love him and he's great in every way... But lately I've noticed his penis kind of stinks... Like really bad... Most guys I've dated were uncircumcised and they didn't smell bad and he IS circumcised and it smells AWFUL! Thing is... He has an abusive home life and is very emotional and clingy and I don't want to hurt his feelings. He's spent his whole life hearing nothing but insults from people whether they were family or peers. How can I tell him without hurting his feelings because the last thing I want to do is he responsible for making him cry.

Edit: His house doesn't always have hot water so maybe that's it. Ik it's not an std