The vagina is a muscular tube so cannot 'loosen' - the idea it can become 'loose' is a sexist myth used to control women's sexuality by implying a woman who has 'too much' sex becomes worth less to men - it will only be tight when not aroused and if the woman is tense so the vaginal muscles tense too. There are genetics too, some women have larger vaginas just like some men have larger penises, sometimes bigger penises work better with larger vaginas but sometimes smaller penises work better with larger vagina's - depending on what part of the vagina is being stimulated. Lots of sex prior and after penetration, and using appropriate sexual positions during penetration prevent any issues with pairing. so coming to your question i do not think if it affects. If you can push a baby. How can just a mere big penis have an effect. At the end of the day your ***** will come back to its original size. Your vagina will resume back to its size. So when you will be having sex with your ex, it will feel just like the past. Do not worry about it. I hope my information ahs helped you.
Theoretically it could but I doubt it. I wouldn't worry about this and put it out of your mind so you can enjoy reconciling with your ex. good luck