In fellatio the -us is replaced by the -io; the declension stem ends in -ion-, which gives the suffix the form -ion cf. The -io n ending is used in English to create nouns from Latin adjectives and it can indicate a state or action wherein the Latin verb is being, or has been, performed. Further English words have been created based on the same Latin root. A person who performs fellatio upon another may be termed a fellator; because of Latin's gender based declension , this word may be restricted by some English speakers to describing a male. The equivalent term for a female is fellatrix. Fellatio can be sexually arousing for participants, and males commonly experience orgasm and ejaculation of semen during the act.