Birthday gift for soon to be ex husband?

Our marriage looks doomed. We are heading for divorce but have not filed. Still living together but sleeping and leading separate lives. Mostly its him who wants the divorce, but I have agreed to go for it. His birthday is coming up in 3 weeks. Its special because its the 40th and he has no family here. Should I get him a gift? If yes, what sort of gift will be appropriate? I don't want him thinking this is a desperate move. I have decided once the divorce is finalized, I am not planning to be his friend, its too painful. So it will probably be the last gift, if I am giving at all.