Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: Even if he sat between her legs, half the dower (mahr) is still to be paid.
There is a break in its chain between al-Sha'bi and Ibn Mas'ud.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14478