I got to learn that this thing was well known in many societies if old. For many centuries Western European medieval and early modern sources mention couples which, due to obesity if both partners or one partner, could not perform sex with penetration either in some poses (missionary first of all) ir even in any pose. The church authorities mentioned the first of this situations ( when missionary sex is fully impossible due to fatness of one or both partners) as only excuse for using of other positions (they were prohibited by the church in general), and there were discussions what is worse from the church point of view in such cases when missionary position was impossible due to fatness - to use another position or to abstain of any sexual consummation of married life at all (oral and hand sex were prohibited as sins at any case). There were also discussions if it is permissible to use help of other people in conjugal sex when its difficult or impossible without help due to obesity of both or one partner
Some byzantine texts express moral reproaches to such families, that, when seeing that their children grow rapidly too fat and soon would be too fat for penetrative sex, dont try to stop it snd to return these young offsprings to modest life, but just try to marry them as quickly as possible, so that at the very moment of marriage they would be still able to consummate it with penetrative sex, in any position and even with any help, and these families arei fully indifferent to the further possibilities of the couple, they care only for the fact that the brides would be able for penetrative sex just after marriage, to consummate it.
Some variants of Tale of beautiful slavegirls in Arabian Nights states, thst one of the beauties (a Fat one) is so fat that she cant be penetrated at all by any partner in any pose. And still she is sexually attractive. In other variants it is said that it is very difficult but still possible to penetrate her.
3 years