What would you do in this situation?

k, this is a weird question but when a guy takes off his pants, and he's really small.. what do you do? like i was with this guy and he was amazing with his hands, and then he took off his pants and he was literally like 3 inches.. hard. i know the average size is 6inches. but come on, he was hard. he wanted to have .. we were a bit drunk and i was like "uhmm.. i have to pee" and then i went and said i was too tired. i felt bad.. but it was like disappointing. i know it's not all about size, but that was the smallest i've ever seen. i don't mean to sound low and i'm sure if you were in this situation you wouldn't know what to do either.. so like how do you like decline without it being obvious?