All perfect praise is due to Allah, The Lord of The Worlds; and may His peace and blessings be upon Prophet Mohammad and upon all his family and companions.
According to the majority of the Muslim scholars, it is recommended for the one intending to offer an Udh-hiyah not to get his hair cut or his nails pared on the first ten days of Thul-Hijjah till he has offered his sacrifice. This is based on the Hadith of Um Salama (May Allah Be Pleased with her) who reported that the Messenger of Allah (PBUH) said: "When anyone of you intends to sacrifice the animal and enter in the month of Dhul-Hijjah, he should not get his hair cut or nails pared till he has offered his sacrifice." [Moslim].
Al-Imam Assayooti (May Allah have mercy on him) said: "It is disliked for one who intends to offer an Udhiyah to get his hair cut or his nails pared on the first ten days of Thul-Hijjah. The wisdom is to spare the whole parts of that person`s body from Hell Fire. It was also said to imitate the pilgrims in their state of Ihram." [Sharh Assayoti Lisonan An-Nassa`i vol.7/pp.212].
However, it is neither reprehensible nor forbidden for one intending to offer an Udhiyah to make love to his wife or to wear perfume. In fact, the reprehensibility is related to the paring of the nails and the cutting of the hair. This is based on the Hadith narrated by A`isha (May Allah be pleased with her) who said: "I used to twist the garlands for the Hadi of Allah's Apostle and he used to send his Hadi to Ka'ba but he never used to regard as unlawful what was lawful for men to do with their wives till the people returned from the Hajj." [Bukhari].
In conclusion, if the person intending to offer an Udhiyah gets his haircut or his nails pared, then his Udh-hiyah is both valid and acceptable. And Allah Knows Best