ty for your courage to ask us. since you asked there are so many underlying questions. In the surface we can only hear your side. Family dynamics are always nuance.

1. Reading your note, you do not appear to be pleased of the situation. My question then is, is this a family tradition or one off thing? If one off then I'd suggest you speak with your wife on how you feel about the situation, why you feel the way you do. Eg finacial implications, common respect for you and your family. If you want this to happen going forward or if you do not want this to happen and why.

2. If it is tradition, meaning you always pay for your relatives to come over then you may want to ask yourself, what has changed? What your in-law's behaviour causes you to feel this way?

Speaking with your wife about how you feel is important so you can be heard, help her understand your feelings and where it is coming from. In exchange, lend your ears to your wife so you can hear here side too. Perhaps there is a deeper reason why she asked your in-law.

Either way, it is best to deal family matters privately. Between husband and wife, it is healthy to speak with her first. Then whatever you both decide, you can be around when she decide to speak with her sister or if it is best to speak with her sister alone.

The important thing is to make sure you and your wife are on the same page. If not, acknowledge where you can both compromise. It is always better to agree where are your boundaries as a married couple and communicate it accordingly to those outside your marriage.

Nothing cannot be solved with a proper communication, empathy and a sense of curiosity. ☺️

Hope it helps and you got this 💪👌🫂