My DH & I bought my BIL children gifts. By the end of the day the gifts would've been opened we hadn't received a text/call to say Thankyou. Eventually my MIL (who was staying with them at the time) text us to say Thankyou. I was really annoyed that the Thankyou had come from my MIL rather than my BIL who upto now has not acknowledged the gifts we bought. I mentioned it to my MIL who didn't seem to grasp how inappropriate it was for her to text us on there behalf. IABU to be annoyed about this?