Nothing new in bed

hello guys! I'm from Ukraine. English is not my first language but I'm gonna try to write as clear as I can. I have a trouble. it's been a few years that I have only one partner. Sex has always been brilliant and we figured out how to orgasm together at the same time. But still two or three months have been a little boring if talk about sex. it is always predictable when it happens and there is nothing new in bed since the end of the spring. Need your advice on this problem, ladies. I want to refresh our sex life!