Mating problem..or not?

Ok, Rocky and Fluffy are trying to mate, but I won't let them....I don't if it is an ok deal or not..he is fixed, she isn't yet,,I have her scheduled next week to get spayed,,,I think someone on here said it was mating season but I am not sure if I read wrong...should I just let them do their thing or stop them? She gets in this position on her tummy lifting the hind legs up, and he lays on her..it is obvious what they are trying to do..Thanks in advance for any help!!

Keep them separated until she gets spayed. Even though he is neutered, there is a slight possibility he could hurt her in the act of what he believes is mating.

Ok, Thank you..I will seperate them if I notice anymore activity like this..or at least if I see the anticipation from either....