Ways to settle my horse?

My 8yo standardbred gelding has... i spose u could say... fallen in love with my 23yo clydie mare. Now when i take my clydie out for a ride he bucks and rears and canters around the paddock whinying like an idiot. Im not sure whether hes just jelous or misses her. He is usually fine if you take him out by himself or if you take him out with her. But I dont know how to stop him carrying on when I take my clydie out. they are the only two horses on the property if it helps. any ideas?? I want to be able to go out riding on my clydie as well as my standardbred. Not only do I enjoy it, but she needs the excersise at her age. Thx... PLZ hlp me Xx