A Friend in Need
Families tend to view relationships with an eye toward future commitments, yet their younger members might just want to spend a few years having fun. Rather than looking for a serious relationship, they want someone completely off the rails as far as their family is concerned. When it is time to bring someone with them to a family event, they might be a friend in need. Finding someone suitable to introduce to the older members of their family could require them to ask a friend to pretend they are dating because they are well within the boundaries the family has for a suitable companion.
It can be awkward to ask a friend for a favour of this magnitude, yet a person within their circle is probably one who can understand their need. Being presented to a family under these circumstances lends its own value to a friendship. Knowing their friend feels comfortable enough to let them know they are an acceptable person by family standards can boost the relationship onto a higher level.
Attending family events without a long history together can make a date uncomfortable, yet the person being asked to pretend they are in a relationship might be more comfortable with the entire situation. The impression they will make on the family could be very favourable because they have a history with their date, yet they do not feel the same pressure to impress everyone.
While this type of favour has occasionally turned into a dating relationship for some, plenty of friends have remained only friends. They might occasionally still find the need to attend each other's family events, yet they will spend the rest of their time pursuing their own relationship goals. Happily ever after could take some time for each of them, but their families will be happy until they do find it.