I want to swallow for my husband's birthday
Why do you want to swallow?
You see, I've been doing my research on the internet and this act of swallowing semen is very good for the skin.
If you want to do something nice for somebody, you have to be okay with it. They will not feel good about it you don't really want to do it.
I just want to try it but I won't do it again if there is no benefit.
That seems to be a good way to approach. Just make sure that you are doing it because you want to.