I was in a co-ed fraternity on campus during college. We did socials with other groups, a semi formal, and a formal. Sometimes we did socials with other co-ed groups on campus, but we were 90% female (there were about 60 girls and 6 guys in our group at one time) so we also we also were able to plan socials with IFC groups without it being awkward. We also partnered with IFC and NPC groups for homecoming, their philanthropy events, and our philanthropy event.
The yellow roses are a great idea though. On a side note, freeze pops are yummy! Unless we are wearing white.