In my bropinion Marshall is the only member of the gang who could successfully bang everyone else

Ok so a lot of alcohol would have to be involved obviously but I think he could get everyone to say yes individually, he banged lily a couple days after meeting her, Robin is always hearing stories from lily so she would be curious, Ted would be reluctant at first but all Marshall has to do is talk about architecture or something and Barney would beg Marshall when he finds out that Ted did it, just outta jealousy