Blue tits nesting

Hi, new to the community and looking for some help or advice . I put up a nesting box last year and the first week or so I had a pair of blue tits nest and leave the nest with 9 chicks . All good . This year I had plenty of sightings of blue tits and Coal tits viewing the box but none seemed to take up residence. Yesterday 24th of april I have what appears to be 2 pairs of blue tits building a nest in the box. 3 tits definitely. 2 are doing the wiggle dance in and around the entrance and seem to be squabbling whilst the other ones look on . Is this 2 females attatched to one male tit and how will it end ? Hope someone has prior experience on this