If your future inlaws are not even acknowledging there's any favoritism, what do you think you will able to say or do to point it out to them? All you can do is make suggestions if they ask what he'd like. You can invite them to spend more time with him--and you--while they are visiting. Sounds like, even though Mike wasn't married to his daughter's mom, his parents established some type of bond that allowed them to have a lot of time raising this granddaughter. But, there are so many other reasons for their being aloof that you can make yourself crazy trying to guess them all. Frankly, your future inlaws just might not have the stamina for dealing with a strongwilled grandson who is still learning boundaries and behavior. Who knows? There are some people who just don't have the patience or energy to deal with children at all stages of life. Some are your greatest help when they are infants and toddlers; some can handle them throughout; some are useless until they are well out of diapers and ready ofr high school. You cannot compare a 10-year-old granddaughter to a 3-year-old grandson. They are different in their needs and their personalities. A 10-year-old is much more independent than a 3-year-old and you don't know when that 5-7 week visitation started or how. You can't get too distracted by the surface things like toys and such. Your future inlaws might be helping in other ways (like including him in a savings plan or estate plans) or they might be your greatest support in the future, like when your son is 10. Meanwhile, your parents are great and they are here for your grandson's emotional need right now. And, the fact that they include your stepdaughter shows they are just loving and giving people. Love them, in return, and appreciate the bonds they are building within your family. Keep the door open and inviting to your future inlaws and try not to take everything personally--even if it is an issue of favoritism. Be yourself. Let them get to know you and their grandson. Discuss things with Mike and let him address them. But, don't try to force it. It probably wouldn't be a bad idea to get some premarital counseling and decide now how you are going to manage the extended family issues.