Probably the easiest thus far.

Get next hto him. Doesn't matter if he's alone or not, the fact you're a man suffices.

Grab his ass; that alone gets him horny.

Whisper horny things in his ears (which can use despiste being a Gila Monster?), get him riled up.

Eventually he'll make an excuse, or just go with you if you two are alone.

Any secluded place suffices.

Go straight for the ass; no need to risk the venomous glands.

Rim him, maybe gonzo him up so his shiny reptilian ass is glistening.

Shove your meat fast and hard, and fast and hard you go.

He'll moan like a bitch while you do him.

You'll cum pretty quickly; ideally in his ass but marking him all over is a good idea also.

Do this as many times as you want.

Whn he's spent leave the cum-covered gaping slut on the ground, so others may have their turn.