It depends on the guy, honestly. Everybody was a virgin once, after all.
You’ll probably get a range of reactions. Some guys will back off: they want somebody more experienced. Some guys will get way too excited and should be avoided because they’re probably creepy in other respects too.
Most guys, though, will be OK with it, but likely uncertain about how to handle it. In the end, if you don’t make a big deal out of it (and it’s not a big deal), he won’t either.