uro's breeding?! help plz

[Bartman]

well i posted before about how my uro's were acting weird. Today as i was cleaning there tank and watching them for a bit, after taking the wood out to let them see eachother again for a bit, the smaller of the 2 uro's is running around with the bigger one and getting on her (maybe?) back. Then once hes on her back and creeps down and bites her right where her tail starts. I keep saying her but im not 100 percent sure on that..just think ing that because of all this behaviour. Do i have a female and male or 2 males? please help asap im gettin worried bout whether i should split them up for good.