Male cat behaviour

i am new to cats and have adopted 2. Tabasco is a male 11 months and he is neutered, Jessie is 6 months a female and she is not yet neutered. Tabasco is moaning at night and trying to constantly "hump" Jessie...what should i do?
Because i am not use to having cats i am not sure what i should do...

She may be coming into heat and he's helping her out - triggered by the hormones she is releasing. Please get her in and get her spayed before she winds up getting outside and pregnant.

Absolutely! Time to spay!