I agree
Most girls I know would not feel comfortable sharing a condom between them. Even if they do "interactive" duos, the risks associated with using the same condom for intercourse with both of them are not worth it. As Bobbi said, you can change the condom quickly & "playfully" that it does not detract or distract from the experience. Dildoes & toys (especially those used for penetration) should also be covered with a condom, using a fresh condom for each girl/person.
*Something else people may not know: when switching between vaginal & anal sex, even on the same woman, the condom should also be changed. The bacteria found in the anus can be transferred to the vagina, which can cause health risks.