The larger the age gap, the better.
Women are tighter and have less blown out roast beef the younger they are and will also have less sexual experience which ensures they won't be loose asf.
From simple science, the second law of thermodynamics states the Total entropy in a closed system must be Increasing.
A woman having sex with numerous men will therefore have a direct impact on her tightness and visibility of the outside of the vagina. If we model the vagina as an elastic muscle (seeing as it stretches); According to Hooke's Law, there shall be a point where the extension will be proportional to the force exerted on the vagina to cause this extension, provided the limit of proportionality is not exceeded it shall return to it's size.
The issue with holes is they take numerous dicks: subjecting their holes to cyclic stresses. Therefore the vagina may "go back to it's normal size" after one sexual session, but after repeated sessions, the vagina will fail due to cyclic loading (Theoretically if you were to hammer a pillar repeatedly, you could eventually destroy it despite the force you strike it with not being enough to provide immediate deformation).
As such, that is why I believe the larger the age gap, the better. Guys won't have to deal with loose roast beef and can actually feel something when having sex.
Of course for legal reasons you must make sure the foid is of the age of consent.
But a 16 Year old foid in the UK, consenting to have sex with a 50 year old guy? In an ideal society that would be encouraged