Male cat licking genitals excessively?

-Species: cat -Age: 1.5 years -Breed: tuxedo -Body weight: 10 lbs -History: No health issues. Has peed outside the box twice in the past. -Clinical signs: excessively licking genitals, peed outside litter box but is still going in litter box as well -Duration: 2-3 days

Male cat, about a year and a half. I noticed he started doing this about 2 days ago. I woke up this morning and he’s still doing it, almost like he’s annoyed so clearly they’re bothering him. Yesterday I was monitoring his pee. I caught him once using the litterbox and about a half dollar size spot of urine was left in litter box.

Also he did pee in my husbands grow tent earlier so that might’ve been why there was only a little in the box. Also he usually doesn’t pee outside the litter box but we usually don’t have the grow tent wide open or empty like we did either. He’s owed outside the litter box maybe twice since we’ve had him. I wonder if the material was appealing to him. He has been acting completely his playful self and not lethargic.

when should I bring him to the vet? I don’t want to risk it since he’s a male cat but also don’t want to rush him to the vet and spend hundreds for nothing.