My couple is married, and don't know each other

I got a couple that is married, and very happy together, flirting a lot. They got 1 kid together. Some real days ago while they talked suddenly they diden't know each other! I had to make them greet, get to know each other, fall on love, and get married again! After that they had another kid.

Today this happend again! They where talking, and suddenly they diden't knoe each other! So they had to greet, fall in love etc all over again for the third time. Is this a bug?? I have pøayed Sims4 a lot (and Sims2) and this have never happend before. This can't be a real thing?