How soon is too soon to have sex with a new partner? It is one of those intractable dating dilemmas. No-one wants to get it wrong and look. Or should you wait until you've gone out on a few more dates before sleeping together? Waited: had sex the day before we got together . I liked him so much that I didn't want to 'ruin' it by sleeping with him too soon. Most notably: Fewer people want sex on the first date. on that front; 63 percent thought there was a number of sex partners that was too many.