First off you have to make sure both rabbits are fixed. Two unfixed rabbits will be territorial and will fight. You can't just put two unaltered rabbits together and expect things to go well.

You don't want babies. I know they're cute but it's more involved then you think. So that is why i strongly suggest you get them fixed. At least for now get the male neutered. It will be less expensive for the male, and it's easier for the vet to do the surgery. This is what more than one vet told me.

Anywho, when rabbits are fixed, they're less aggressive and not territorial. What happens when a rabbit isn't fixed is, they poop everywhere to mark their territory, they chin rub, and spray urine on things. To show other rabbits and animals this is their place.

The reason your male is lifting her tail is because he wants to mate with the female. He only needs to mount her for a few seconds to get her pregnant. So now that you know he's mounted her, he probably already got her pregnant.

The female is exhibiting the typical behavior of an unaltered one. She most likely doesn't want to be bothered. This just sounds to me like typical unaltered rabbit behavior. And i strongly suggest you get them fixed if you really want a bonded pair. Any rabbit will usually act this way. I have seen this happen with two unaltered males also. In my experience only two females unfixed can stay together in one cage. But even they can still exhibit territorial instincts.

You can't just put two rabbits together and expect them to get along, especially when they aren't fixed. Like i said, once fixed they will behave better. They wont be territorial and you won't have to worry about babies. Everything you tried previously will work better. Once fixed you can slowly introduce them to each other. They should be more adaptable and willing to make friends. Most rabbits love to have a friend or more than one friend. But also when pairing, take into consideration that some people have rabbits from the same litter. I've experienced rabbits raised together from the same litter or at least bought together as babies, are likely to become bonded that way. Even mother and daughter. So I'm just describing some ways pairs become bonded. But your rabbit has been alone. He isn't fixed and i feel the only way to make sure of a proper bonding, is to fix him first. Then fix the other rabbit too. So both will then be able to be friends.