Crate and rotate when your are home.
Crate BOTH of them when you are not home. If possible, kennel or crate one in the garage if you have a garage. And the other in the house.
Having the girl do her business in the front yard and the male in the back may be ok.
If you are there, you can stop them before they tie. I mean, he will be licking her and long before he tries to hump, you can lead him away. Mostly the problem is that you think she is out before she is, let them together, go take a shower and come back and whoops, they are tied. And likely there will be puppies. so crate and rotate for a month. Constant supervision. Constant vigilance!!!!
Heidi Ho, Odie
Joy-Joy, Bear Cub, Hepsi-Pepsi
Cujo2, Karma Chameleon
Ramona the Pest, Kojak -- who loves you baby?
Tiny Tinnie, Susie's Uzzi, Kaiah -- The Baby Monster.