keep a spare

To keep some distance in a relationship so as not to get sick of each other.

Girl 1-How are things going with the new man?

Girl 2-Great, we can't keep our hands off each other!
Girl 1-just remember to keep a spare..

Gypsy Spare

Has to do with bowling. When bowling and you miss every pin on the first try and on your second bowl of the frame you hit every pin and get a spare, thus getting a gypsy spare. Named after gypsy waterford the most famous gypsy of them all.

Ahhh must be nice gypsy, you got a gypsy spare i remember when I did that.