Just another thought squeeky, children of either gender learn by watching their parents. My sons saw my husband have a good and relaxed relationship with my parents into older age, sadly my husband's father died before I met him and as his mother was much older she died when our sons were children. We were never geographically close and I would say our relationship was of its time, fairly formal but loving. They grew up seeing us make clear that relationships with parents and family are valuable.
Neither of our sons are geographically close enough to just drop in for a cuppa. They work long hours, have their own homes and families but and this is an important but know their parents as people, are in regular contact (as am I with them, its a two way street). We support them if they need it and they support us if we let them. A close friend is very ill at the moment and daily supportive messages are coming without prompting.
I do know what you mean about seeing closeness between adult daughters and their mothers, I've had the odd pang over the years which has usually passed when I think of how frankly bossy some adult daughters can be and how friends daughters often gravitated to our home in their teenage years when they were fighting with their mothers. Teenage boys seemed to us to be much less volatile. I'm happy that daughters in law and granddaughters are now in my life. Please don't be governed by stereotypes, your relationship with your sons is unique to you all, relax and enjoy them, the future will sort itself.