it depends on your expectations ... if you are ok with someone who has lived with another woman( I would say tried her ) ... and then you meet him ... how would you react if you knew he was ditched by another woman or he ditched another woman or maybe lived together with another woman ... if thats ok with you ... then you should be free enough to keep trying your partners as long u find 'THE ONE' ...

As Mila's comments says - 'Everybody is right, Everybody is wrong, it depends on where they stand '

My experience with woman says they are very possessive about the man they love ... but this 'Living Together' changes that perception ... they are possessive as long as they are together ... this gives a good chance for flirts are least interested in marriages to try out as many girls before they die ...

Trust me ... flirts are good at it ...  

and when you say about premarital sex, I dont approve of that either ...