As someone who is currently in a relationship with a Great Dane lady, I have a little experience. I will start by saying it all starts with building a loving and trusting relationship. Spend time with her, get to know her, and learn her body language. If you are getting her as a puppy, don’t attempt anything sexual on her first heat, just be there for her for snuggles and support while she figures out her own body. Wait until her second heat to actually do anything sexual. As far as having sex with her regularly year round, including out of heat, that really depends on the girl. Some girls, including mine, enjoy sex out of heat, but that’s not the case with all. Because my girl is a Great Dane, I never have any trouble fitting in her in or out of heat (I’m pretty average for a human). Your semen itself poses no real risk to her, but infections can occur if you do not take the right steps to prevent them. For example, before you make love wash Everything like your hands and your dick. Make sure to rinse everything well after washing, you don’t want soap getting in there either. If you are going to be pleasuring your lady orally, you should always brush, floss, and use mouthwash prior to. Always rinse your mouth out with water a few times to make sure you have all of the toothpaste and mouthwash out. After every heat your girl has you should always wait at least two weeks to allow her cervix to close before engaging in any sexual activities again. This helps prevent infections such as pyometrea. And then there’s the age old question of will the vet know. If you are planning a vet visit it is best to abstain from sex for at least a few days. I have personally seen my girl leak my semen three days after we have had sex, and I’ve heard of other people saying their girls have leaked after even more days than that. Whatever the case, it’s best if your lady is not leaking semen while she’s there, so abstain for as many days as you feel necessary. If it’s an emergency don’t let the fear of it keep you from taking her to the vet, her safety always comes first. I wish you luck on getting your own lady ?.